Did you get an answer for the above question?
The ZOOM app seems to behave differently to other webinar providers. e.g. with WebEx you can add the unique credentials of all users so when they access the app on the Canvas they see their webinar ID's in a drop down list. The ZOOM app does not provide for multiple user profiles, there is simply a field in the app on the canvas where you copy the ID from your ZOOM account and then paste it into the canvas element in Eloqua. In addition, ZOOM has omitted to provide you with any on-screen confirmation that the addition of the webinar ID has been successful - pretty sloppy on their behalf, but I've found the pasting of the ID does work.
There's no need for each user to install the app as far as we can see, it just needs to be done once by the Eloqua Admin.
The app is OK, but I've been trying to work with ZOOM on some enhancements that would make it a little more robust.
Still not found a way yet to have multiple zoom accounts being linked to Eloqua.
So far you either have to re-install each time as the user you want to use (but stops working for account that was used) or use a master zoom account and setup the meetings for everyone in that one account.
Not ideal for us as a large global company